gpu: Add GSK_GPU_DISABLE=repeat

This is useful for testing of repeat nodes - both performance
and conformance, and potentially even driver issues with GL_REPEAT.

We have code for manual repeating anyway, so adding a flag to force
always using it is easy.

gsk/gpu/gskgpunodeprocessor.c

@@ -3265,6 +3265,7 @@ gsk_gpu_node_processor_add_repeat_node (GskGpuNodeProcessor *self,
   const graphene_rect_t *child_bounds;
   graphene_rect_t bounds;
   float tile_left, tile_right, tile_top, tile_bottom;
+  gboolean avoid_offscreen;
 
   child = gsk_repeat_node_get_child (node);
   child_bounds = gsk_repeat_node_get_child_bounds (node);
@@ -3279,10 +3280,12 @@ gsk_gpu_node_processor_add_repeat_node (GskGpuNodeProcessor *self,
   tile_right = (bounds.origin.x + bounds.size.width - child_bounds->origin.x) / child_bounds->size.width;
   tile_top = (bounds.origin.y - child_bounds->origin.y) / child_bounds->size.height;
   tile_bottom = (bounds.origin.y + bounds.size.height - child_bounds->origin.y) / child_bounds->size.height;
+  avoid_offscreen = !gsk_gpu_frame_should_optimize (self->frame, GSK_GPU_OPTIMIZE_REPEAT);
 
   /* the 1st check tests that a tile fully fits into the bounds,
    * the 2nd check is to catch the case where it fits exactly */
-  if (ceilf (tile_left) < floorf (tile_right) &&
+  if (!avoid_offscreen &&
+      ceilf (tile_left) < floorf (tile_right) &&
       bounds.size.width > child_bounds->size.width)
     {
       if (ceilf (tile_top) < floorf (tile_bottom) &&
@@ -3320,7 +3323,8 @@ gsk_gpu_node_processor_add_repeat_node (GskGpuNodeProcessor *self,
             }
         }
     }
-  else if (ceilf (tile_top) < floorf (tile_bottom) &&
+  else if (!avoid_offscreen &&
+           ceilf (tile_top) < floorf (tile_bottom) &&
            bounds.size.height > child_bounds->size.height)
     {
       /* repeat horizontally, tile vertically */

gsk/gpu/gskgpurenderer.c

@@ -32,6 +32,7 @@ static const GdkDebugKey gsk_gpu_optimization_keys[] = {
   { "mipmap",    GSK_GPU_OPTIMIZE_MIPMAP,            "Avoid creating mipmaps" },
   { "to-image",  GSK_GPU_OPTIMIZE_TO_IMAGE,          "Don't fast-path creation of images for nodes" },
   { "occlusion", GSK_GPU_OPTIMIZE_OCCLUSION_CULLING, "Disable occlusion culling via opaque node tracking" },
+  { "repeat",    GSK_GPU_OPTIMIZE_REPEAT,            "Repeat drawing operations instead of using offscreen and GL_REPEAT" },
 };
 
 typedef struct _GskGpuRendererPrivate GskGpuRendererPrivate;

gsk/gpu/gskgputypesprivate.h

@@ -139,5 +139,6 @@ typedef enum {
   GSK_GPU_OPTIMIZE_MIPMAP               = 1 <<  4,
   GSK_GPU_OPTIMIZE_TO_IMAGE             = 1 <<  5,
   GSK_GPU_OPTIMIZE_OCCLUSION_CULLING    = 1 <<  6,
+  GSK_GPU_OPTIMIZE_REPEAT               = 1 <<  7,
 } GskGpuOptimizations;
 

gtk/gskpango.c

@@ -211,7 +211,7 @@ gsk_pango_renderer_draw_error_underline (PangoRenderer *renderer,
 
   gtk_snapshot_push_repeat (crenderer->snapshot,
                             &GRAPHENE_RECT_INIT (xx, yy, ww, hh),
-                            NULL);
+                            &GRAPHENE_RECT_INIT (xx, yy, 1.5 * hh, hh));
 
   gsk_rounded_rect_init_from_rect (&dot,
                                    &GRAPHENE_RECT_INIT (xx, yy, hh, hh),
@@ -220,9 +220,6 @@ gsk_pango_renderer_draw_error_underline (PangoRenderer *renderer,
   gtk_snapshot_push_rounded_clip (crenderer->snapshot, &dot);
   gtk_snapshot_append_color2 (crenderer->snapshot, &color, &dot.bounds);
   gtk_snapshot_pop (crenderer->snapshot);
-  gtk_snapshot_append_color2 (crenderer->snapshot,
-                              &GDK_COLOR_SRGB (0, 0, 0, 0),
-                              &GRAPHENE_RECT_INIT (xx, yy, 1.5 * hh, hh));
 
   gdk_color_finish (&color);